Introduction. The HIV prevalence among men who have sex with men (MSM) in China keeps increasing sharply. A high proportion of the MSM in China have male regular sex partner (RP) and prevalence of unprotected anal intercourse (UAI) involving such RP is higher than when non-RP is involved. Trust, intimacy and cognitive factors are the factors associated with UAI with RP. Several cross-sectional studies have been demonstrated the important factors associated with UAI with RP among MSM in China. However, no study about intervention for MSM-RP is found to be conducted. To reduce UAI with RP, an intervention tailored to RP is urgently developed and identified its efficacy. / Objectives. The study aimed to describe the prevalence of UAI, as well as of which associated factors among MSM-RP in Beijing and Chengdu, China, and to evaluate the efficacy of an enhanced HIV voluntary counseling and testing (VCT) in increasing condom use with RP among MSMRP in China by a randomized controlled trial (RCT). / Subjects and Methods. A cross-sectional survey and a randomized controlled trial have been conducted. For the cross-sectional survey, total 307 HIV negative MSM who have RP have been recruited by three ways. Face to face interview has been conducted to participants. Based on the associated factors found in the cross-sectional survey, interventions including video, education leaflets and enhanced counseling contents have been tailored to RP among MSMRP. For the randomized controlled trial, total 336 MSMRP have been recruited and randomly assigned 169 subjects to the Intervention Group in which participants have been given enhanced VCT plus an audio-visual and four leaflets components and 167 subjects to the Control Group in which participants have been given only standard-of-care VCT at the baseline. Evaluation was conducted at Month 3 and 6. Statistical methods such as descriptive analyses, Chi-square test and logistic regression were used in this study. / Results. The results have been found were the prevalence of UAI with RP among MSMRP was 52.4%, and the Theory of Planned Behavior (TPB) related cognitions, trust, intimacy, depression and anxiety were associated with UAI with RP among MSMRP. In the RCT study, participants in the Intervention Group had less UAI (36.1% vs. 49.1%) than those of the Control Group at Month 3. / Conclusions. This study showed a high prevalence of UAI among MSMRP, whilst trust, intimacy and cognitive factors were associated with UAI with RP. The efficacy of Enhanced VCT tailored to RP has been identified. The acceptability and feasibility of the tailored intervention were demonstrated. In the future HIV prevention programs, the effective intervention should be considered to be incorporated into standard-of-care VCT procedures and be implemented in the specific population. / 介紹：中國男男性接觸者中的愛滋病發病率一直保持著上升的狀態。而在中國男男性接觸者中有很大比例存在著固定性伴侶。男男性接觸者同固定性伴發生無保護肛交行為的比例大於其同非固定性伴。信任，親密以及認知因素已經被證實是影響男男性接觸者同其固定性伴發生無保護肛交行為的因素。但是在中國還沒有發現專門針對有固定性伴的男男性接觸者的干預研究。為了降低男男性接觸者同其固定性伴的無保護肛交的發生率，針對有固定性伴的男男性接觸者的干預方法應該被發展同時證實其有效性。 / 目的：本研究目的在於調查北京及成都男男性接觸者的固定性伴的比例，及其影響因素，包括健康行為理論的影響因素以及人際關係因素。同時，本研究也驗證了以隨機對照實驗來評估針對有固定性伴男男性接觸者的提高型愛滋病自願檢測諮詢對減少其高危性行為的效果。 / 對象與方法：本研究由橫斷面研究以及隨機對照試驗組成。在橫斷面調查中，307名愛滋病陰性的有固定性伴的男男性接觸者被招募。基於在橫斷面調查中發現的對男男性接觸者與固定性伴間發生無保護性行為的影響因素，一項專門針對有固定性伴的男男性接觸者的提高型愛滋病自願檢測諮詢干預方法被發展應用了隨機對照試驗中已驗證其有效性。在隨機對照試驗中，169名和167名研究對象被招募並分別被隨機分配到干預組（接受提高型愛滋病自願檢測諮詢）和對照組（接受標準型愛滋病自願檢測諮詢）中。分別於干預後的3個月和6個月回訪進行干預結果的評估。在本次研究中，運用了卡方检验和logistic回歸等統計學方法。 / 結果：在橫斷面調查中發現，男男性接觸者同固定性伴的無保護肛交發生率為52.4%。影響與固定性伴無保護肛交的因素包括：健康行為理論（TPB）相關的認知，信任，親密以及抑鬱和焦慮。在隨機對照試驗中發現，在3個月隨訪中干預組的男男性接觸者與固定性伴發生無保護肛交的比例較對照組明顯降低（36.1% vs. 49.1%）。 / 結論：本研究結果顯示中國男男性接觸者的固定性伴的比例很高，同時幾乎一半的有固定性伴的的男男性接觸者同時有多個性伴，這就有增加感染愛滋病及其他性病的風險。一項針對有固定性伴的男男性接觸者設計的提高型愛滋病自願檢測諮詢方法在降低其危險性行為上的可接受性和有效性已經被證實。提示在今後的愛滋病干預項目中可以進一步的推廣應用。 / Li, Chunrong. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 149-178). / Abstracts and appendixes also in Chinese. / Title from PDF title page (viewed on 05, October, 2016). / Li, Chunrong. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.